Nickel-base weld metals initially used in the world involved coated electrode 182 (15% Cr) and TIG wire or strip 82 (20% Cr). A significant field experience (more than 300 cases) involving PWSCC has been observed, particularly these last 5 years on 182 with limited cases on 82. They seemed to occur in non stress-relieved or repaired or severely cold worked welds without stress relief treatment (SR).Weld metal 182 is sensitive to SCC in laboratory conditions, the cracking is always intergranular and interdendritic. It involves an initiation period (including some slow propagation regime) and a rapid propagation regime. The time for initiation decreases at high C and Si contents. The activation energy of the process is assessed at 185 kJ/mol, the stress threshold is close to YS (350 MPa), not affected by some gentle cycling. A detailed analysis of the microstructure has not provided any clear explanation for the behaviours of as-welded I stress relieved (SR) materials : the better SCC resistance of SR (610°C) components could be due partly to a stress relaxation and to some recristallization in the superficial cold worked layer.The discrepancy between the various crack growth rate data arises from the experimental difficulties of measurements due to uneven fracture surfaces, different test procedures between labs (static I cyclic loading) and the strong orientation resulting from the welding. Taking into account a significant lack of data at low K values, different reference curves for da/dt versus K are proposed. The activation energy is closed to 130 kJ/mol but some laboratories propose a value of 240 kJ/mol. The orientation of the specimen has a marked effect on the CGRs, the fastest CGRs (x3) are obtained when the cracking occurs in the direction of the dendrites. The SR treatment at 610°C introduces a beneficial influence of a factor 2-3.5. The chemical composition of weld metal 182 has a limited (but not understood) effect on SCC crack growth rates. Cold work (10%) increases CGRs by a factor 2-3.Weld metal 82 is also sensitive to SCC, but its resistance is greater than for weld metal 182: factor at least 6 on the time for initiation at high stress level, 360°C. CGRs are assumed to be 2.6 lower than those of 182. Weld metals with 30% Cr (152 and 52) appear to be very resistant to PWSCC, since no cracking was observed at 360°C. Even very severe tests (SSRTs with welding defects in the specimens) have failed to promote SCCWeld metals could suffer a very significant reduction of the fracture resistance in hydrogenated water at low temperature (LTCP at 50 to 150°C). Hydrogen content in water (in the range 15 to 150 cc/kg) decreases this fracture resistance in the case of weld metal 82, and to a lesser extend of weld 52, particularly when the temperature is decreased from 150°C to 50°C. Investigations are in progress in order to assess the lack of redhibitory effect during shutdown.Ni base weld metals frequently present hot-cracking defects (currently 500 um), as a result of the welding process and the chemical composition. This problem is of particular concern with regard to weld metals with 30% Cr, which have proved a greater sensitivity to hot-cracking than welds with 15-20% Cr, despite the Cr content is not the right explanation. Nevertheless, they exhibit a good ability to welding during manufacturing and alloy 52 is now proposed for repair and welding of tubes to tubesheet, though alloy 52 was not used for this welding in replacement steam generators and in the last series of plants in EDF.A significant effort has still to be done to increase the level of confidence in the results obtained with weld metals. With regard to SCC, an experimental and theoretical approach is under way to precise the influences of parameters in laboratory. Preliminary LTCP results need an experimental confirmation together with a better assessment for the application to plants during shutdown.